<article><hdr>Aerial shot of a Curtiss P-60</hdr><body>
<hi style=afpcap>The success of the P-40 lead to several development programmes to capitalise on the design features of the Warhawk. The P-40 was upgraded to become the P-46 and the P-53 although the latter version was not built as its design was replaced by the P-60 fitted with a Rolls Royce Merlin power plant. However only five were constructed, as the Army preferred the Merlin engined P-51 for fighter escort duties.</hi>
